Respiratory Flashcards
COPD
Pathophysiology
- Non-reversible, long-term deterioration in air flow in the lungs
- Damage to lung tissue → obstruction of air flow → more difficult to ventilation lungs → more prone to infections
COPD
Causes
- Smoking!
- Alpha-1-antitrypsin deficiency
- Cadmium
- Coal
- Cotton
- Cement
- Grain
COPD
Features
- Cough - often productive
- Dyspnoea
- Wheeze
- Recurrent respiratory infections
- Severe cases: RHF → peripheral oedema
COPD
how to quantify breathlessness?
MRC dyspnoea scale
- Grade 1 = breathless on strenuous exercise
- Grade 2 - breathless on walking up hill
- Grade 3 - breathless that slows walking on the flat
- Grade 4 - stop to catch their breath after walking 100 meters on the flat
- Grade 5 - unable to leave house due to breathlessness
COPD
Investigations
Clinical presentation and spirometry!
Spirometry:
- FEV1/FVC ratio < 70%
CXR:
- Hyperinflation, bullae, flat hemidiaphragm
High res CT scan:
- Emphysema/chronic airway disease
Others:
- ECG, echo, sputum, alpha1AT, FBC, BMI, TLCO
COPD
Severity
All with post-bronch FEV1/FVC < 0.7
FEV1 (% predicted):
- Stage 1 (Mild): > 80% (+ symptoms)
- Stage 2 (Mod): 50-79%
- Stage 3 (Severe): 30-49%
- Stage 4 (Very severe): < 30%
COPD
General management
- Smoking cessation - offer nicotine replacement therapy
- Vaccines = one-off pneumococcal and annual flu vaccines
- Pulmonary rehabilitation - start early, as soon as feeling breathless with regular activity
COPD
Medications
- SABA or SAMA
If asthmatic features:
- SABA/SAMA + LABA + ICS
- Then triple therapy (remove SAMA if add LAMA)
If no asthmatic features:
- SABA + LABA + LAMA
- Then triple therapy (+ ICS)
COPD
What are the asthmatic features
- Any previous, secure diagnosis of asthma or atopy
- Higher blood eosinophil count
- Substantial variation in FEV1 over time (≥ 400 ml)
- Substantial diurnal variation in peak expiratory flow (≥ 20%)
COPD
Oxygen therapy
- If retaining COaim for oxygen saturations of88-92%titrated byventuri mask - start with 28%
- If not retaining COand their bicarbonate is normal (meaning they do not normally retain CO) then give oxygen to aim for oxygen saturations> 94%
COPD
Complications
- Polycythaemia
- Cor Pulmonale
COPD
Factors that improve survival
- Smoking cessation
- LTOT
- Lung volume reduction surgery in selected patients
COPD
Exacerbation
Features
- Increase in dyspnoea, cough, wheeze
- May be increased in sputum suggestive of infective cause
- May be hypoxic and in some cases, have acute confusion
COPD
Exacerbation
Causative bacterial organisms
- Haemophilus influenzae (most common)
- Streptococcus pneumoniae
- Moraxella catarrhalis
COPD
Exacerbation
most common viral cause
- Human rhinovirus
COPD
Exacerbation
Management
- Increase frequency of bronchodilator
- 30 mg Prednisolone PO for 5 days
- Nebulisers
- Abx only if sputum is purulent or there are clinical signs of pneumonia
- Amoxicillin, Clarithromycin or Doxycycline
Lung cancer
Types
NSCLC (80%)
- Adenocarcinoma
- Squamous cell carcinoma
- Large-cell carcinoma
SCLC (20%)
- Contain neurosecretory granules that can release neuroendocrine hormones –> responsible for many paraneoplastic syndrome
Lung cancer
Features
- Persistent cough
- Haemoptysis
- Dyspnoea
- Chest pain
- Weight loss/anaemia
- Recurrent pneumonia
- Hoarseness (pancoast tumour on recurrent laryngeal nerve)
- Superior vena cava syndrome
- Fixed, monophonic wheeze
- Supraclavicular lymphadenopathy or persistent cervical lymphadenopathy
- Clubbing
Lung cancer
Investigations
- 1st line = CXR
- Staging CT scan
- Bronchoscopy with biopsy
Lung cancer
Referral
2-week wait referral
- CXR findings that suggest lung cancer
- > 40 yrs with unexplained haemoptysis
OFFER urgent CXR (within 2 weeks):
- > 40 yrs with 2 or more of following unexplained symptoms, or ever smoked and 1 of the following unexplained symptoms:
- Cough
- Fatigue
- SOB
- Chest pain
- Weight loss
- Appetite loss
CONSIDER urgent CXR (within 2 weeks):
- > 40 yrs with any of following:
- Persistent or recurrent chest infection
- Clubbing
- Supraclavicular lymphadenopathy or persistent cervical lymphadenopathy
- Chest signs consistent with lung cancer
- Thrombocytosis
Lung cancer
Management
NSCLC
- Surgery if possible (lobectomy)
- Mediastinopathy prior to surgery to show lymph node involvement
- Curative or palliative radiotherapy
- Poor response to chemo
Lung cancer
Management
SCLC
- Surgery if early disease (T1-2a, N0, M0)
- Combination of chemo and radiotherapy
- Poorer prognosis than NSCLC
Pneumonia
Features
3 features on auscultation?
- Productive cough
- Chest pain - may be pleuritic
- Dyspnoea
- Fever
- Tachycardia
- Reduced O2 saturations
- Auscultation:
- Reduced breath sounds
- Bronchial breathing
- Focal coarse crackles
Pneumonia
Causes
- Streptococcus pneumoniae
- Haemophilus influenzae
- Staphylococcus aureus
- Mycoplasma pneumoniae
- Legionella pneumophilia
- Klebsiella pneumoniae
- Pneumocystis jiroveci
Pneumonia
HAP time frame?
Develops > 48 hrs after admission and within 2 weeks of discharge
Pneumonia
Investigations
- Sputum culture
- Bloods - raised inflammatory markers, U&Es for urea for CURB65
- ABG if low sats/COPD
- CXR - consolidation
- Atypicals antigen testing
Pneumonia
CURB-65 and scores
Confusion (< 8/10) Urea > 7mmol/L R: RR > 30 B: BP < 90mmHg systolic or 60 mmHg diastolic 65: > 65 yrs
0-1: Home treatment
1-2: Hospital treatment
3+: Consider intensive care
Pneumonia
Management
Mild:
- 5 day course of PO Amoxicillin (or macrolide)
Mod-Sev:
- 7-10 day course of dual Abx therapy
- Amoxicillin and a macrolide
Repeat CXR at 6 weeks
Pneumonia
Complications
- Sepsis
- Pleural effusion
- Empyema
- Lung abscess
- Death
Pneumonia
S. pneumoniae
- 80% of pneumonia cases
- High fever, rapid onset
- Herpes labialis (cold sores!)
Pneumonia
H. influenza
- Particularly common in COPD patients
Pneumonia
S. aureus
- Often in patients with influenza infection or CF
Pneumonia
Mycoplasma pneumoniae
- Atypical
- Dry cough, atypical chest signs/XR findings
- Autoimmune haemolytic anaemia
- Erythema multiforme
Pneumonia
Legionella pneumophilia
- Atypical pneumonia
- Hyponatraemia
- Lymphopenia
- Air conditioning units (recent cheap holiday)
Pneumonia
Klebsiella pneumonia
- Classically in alcoholics
Pneumonia
Pneumocystis jiroveci
- FUNGAL
- HIV
- Dry cough
- Exercise-induced desaturations
- Absence of chest signs
- Treat with co-trimoxazole (Trimethoprim and sulfamethoxazole)
PE
Features
- Tachypnoea
- Chest pain - typically pleuritic
- Dyspnoea
- Haemoptysis
- Tachycardia
- May have fever
Resp exam:
- Clear chest or crackles
PE
Risk factors
- Immbolity
- Long haul flihgts
- Recent surgery
- Pregnancy
- Hormone therapy with oestrogen
- Malignancy
- Polycythaemia
- SLE
- Thrombophilia
PE
PERC criteria
All must be negative to rule out PE
- Age > 50
- HR > 100
- O2 sats < 94%
- Previous DVT or PE
- Recent surgery or trauma in past 4 weeks
- Haemoptysis
- Unilateral leg swelling
- Oestrogen use (e.g. HRT, contraceptives)
PE
Wells Score
- Clinical signs and symptoms of DVT (3)
- Alternative diagnosis is less likely (3)
- HR > 100 bpm (1.5)
- Immobilisation for > 3 days or surgery in past 4 weeks (1.5)
- Previous DVT/PE (1.5)
- Haemoptysis (1)
- Malignancy (on treatment, treated in last 6 months, or palliative) (1)
PE
Investigations following Wells Score
If PE likely (> 4 Wells):
- CTPA
- Anticoagulation in the meantime (DOAC)
- if negative –> proximal leg vein USS if DVT suspected
If PE unlikely (< 4 Wells):
- D-Dimer
- If positive –> CTPA
- If negative –> PE unlikely, stop any anticoagulation
Renal impairment –> use V/Q scan instead of CTPA
PE
Other investigations
- ECG: S1Q3T3
- CXR: typically normal, use to rule out other pathology
- ABG: sometimes respiratory alkalosis with low pO2
PE
Management
- Anticoagulation with DOAC (unless renal impairment or antiphospholipid syndrome –> LMWH)
- Provoked vs unprovoked: 3 months for provoked, 6 months for unprovoked, 6 months for active cancer
- If haemodynamically unstable–> Thrombolysis (e.g. alteplase)
- If repeat PEs despite adequate anticoagulation –> consider IVC filter
TB
Pathophysiology
- Mycobacterium tuberculosis: rod-shaped, acid-fast bacilli
- Macrophages engulf the TB bacteria but TB bacteria secretes enzymes to inhibit its own breakdown -> encapsulated within macrophage -> proliferates -> caseous necrosis -> Gohn Focus
- Gohn Focus + hilar lymph nodes = Gohn Complex
Can stay like this as latent TB, then may reactivate if immunocompromised or in older age
TB
Types
- Primary: Gohn complex etc
- Secondary: reactivation, mostly in apex, cavitating lesions
- Systemic miliary TB - spread via vascular system to other areas of the body
TB
Extra-pulmonary infection
- CNS (Tb meningitis)
- Vertebral bodies (Pott’s disease)
- Cervical lymph nodes (scrofuloderma)
- Cold abscesses - usually on the neck
- Renal (sterile pyuria, WBCs in urine)
- Adrenal glands (Addisons)
- Liver (hepatitis)
- Cutaneous TB
TB
Features
- Fever
- Night sweats
- Weight loss
- Haemoptysis
TB
Investigations
CXR
- Primary TB: patchy consolidation, pleural effusions, bilateral hilar lymphadenopathy
- Reactivated TB: patchy or nodular consolidation with upper lobe cavitation
- Disseminated miliary TB: millet seeds appearance
Sputum smear
- 3 specimen
- Use hypertonic saline or bronchoscopy with lavage if not producing sputum
- Ziehl Neelson stain -> red on blue background
- Done on Lowenstein-Jensen growth medium
Sputum culture
- Gold-standard
- Can assess drug sensitivities
- Can take 1-3 weeks
TB
bCG vaccine
- Intradermal infection of live attenuated TB
- Do Mantoux test prior to the vaccine - only give if negative
- Assess for immunosuppression/HIV
- Offer to high risk:
- Neonates born in areas with high rates, with relatives from countries with high rates, Fx
- Unvaccinated children/young adults (<35yrs) with close contact
- Unvaccinated children/young adults who have recently arrived from high risk country
- Healthcare workers
TB
Management of active TB
Initial 2 months:
- Rifampicin
- Isoniazid
- Pyrazinamide
- Ethambutol
Further 4 months:
- Rifampicin
- Isoniazid
PLUS Pyridoxine (Vit B6) for full 6 months
TB
RIfampicin SEs
- Red and orange urine
- Hepatitis
- Liver enzyme inducer
TB
Isoniazid SEs
- Peripheral neuropathy (Vit B6 helps)
- Hepatitis
- Liver enzyme inhibitor
- Agranulocytosis
TB
Pyrazinamide SEs
- Hyperuricaemia -> gout
- Arthralgia and myalgia
- Hepatitis
TB
Ethambutol SEs
- Difficulty recognizing colours
- Check visual acuity before and during treatment
TB
Management of meningeal TB
- Prolonged period of 12 months of treatment
- PLUS steroids
TB
DOTS
- Directly observed therapy
- 3 times a week
- For those in certain groups, e.g. homeless people with active TB, likely to have poor concordance, all prisoners with active or latent TB
TB
Risk factors for reactivation of TB
- Silicosis
- Chronic renal failure
- HIV
- Solid organ transplantation with immuosuppression
- IVDU
- Anti-TNF treatment
- Previous gastrectomy
- Older age
TB
Screening for latent TB
Mantoux test
- Purified protein derivative (PPD) - tuberculin
- Injected intradermally
- Result read 3 days later
- Positive = had TB infection at some point
- False negative may be seen in miliary TB, sarcoidosis, HIV, lymphoma, very young age (< 6 months)
Interferon-gamma blood test
- Looks for evidence of previous TB infection
- Used in mantoux positive or equivocal, people where tuberculin test may be falsely negative
- If has BCG, does not show positive (a bonus)
If either are positive -> CXR to look for active infection
TB
Treatment of latent TB
- 3 months or ‘RI’ (+ pyridoxine)
OR - 6 months of Isoniazid (+pyridoxine)
Spirometry
Restrictive pattern
- Reduced FEV1 < 80%
- Reduced FVC <80%
- Normal FEV1/FVC ratio >0.7/75%
- Reduced TLCO
Spirometry
Obstructive pattern
- Reduced FEV1 < 80%
- Reduced FVC (but to a lesser extent than FEV1)
- Reduced FEV1/FVC ratio <0.7/75%
Spirometry definitions
- FEV1: forced expiratory volume - volume that has been exhaled at the end of the first second of forced expiration
- FVC: forced vital capacity - volume that has been exhaled after a maximal expiration following a full inspiration
Spirometry graphs
- Obstructive: more gradual upwards trajectory, less flat
- Restrictive: same shape of trajectory but lower on the graph
Interstitial lung disease
Definition
Umbrella term to describe conditions affecting the lung parenchyma
Fibrosis –> replacement of normal elastic and functional lung tissue with scar tissue that is stiff and does not function as effectively
Interstitial lung disease
Upper lobe diseases
CHARTS
Coal workers pneumonia Histiocytosis/Hypersensitivity pneumonitis Ankylosing spondylitis Radiation Tuberculosis Silicosis/sarcoidosis
Interstitial lung disease
Lower lobe diseases
ICDA
Idiopathic pulmonary fibrosis
Connective tissue disorders, e.g. SLE
Drug-induced: amiodarone, bleomycin, methotrexate
Asbestosis
Interstitial lung disease
Diagnosis
- CXR: ground glass changes
- Lung biopsy
Interstitial lung disease
Management
- Remove/treat the underlying cause
- Home oxygen is hypoxic at rest
- Stop smoking
- Physio and pulmonary rehabilitation
- Flu and pneumococcal vaccines
- Advanced care planning
- Lung transplant - weigh up risks vs benefits
Idiopathic pulmonary fibrosis
Epidemiology
- 50 - 70 yrs
- Twice as common in men
Idiopathic pulmonary fibrosis
Features
- Insidious onset of SOB, dry cough > 3 months
- Bibasal fine inspiratory crackles and clubbing
Idiopathic pulmonary fibrosis
Investigations
- Spirometry: restrictive picture
- Reduced TLCO
- High resolution CT = needed for diagnosis
- CXR
Ground glass changes and honeycombing
Idiopathic pulmonary fibrosis
Management
- Pulmonary rehabilitation
- Supplementary O2
- May need lung transplant eventually
- Pirfenidone or Nintedanib may be used
Idiopathic pulmonary fibrosis
Prognosis
2-5 years
Drug causes of pulmonary fibrosis
- Amiodarone
- Cyclophosphamide
- Methotrexate
- Nitrofurantoin
- Bleomycin
What is the TLCO
Total gas transfer!
The transfer factor describes the rate at which a gas will diffuse from alveoli into blood. Carbon monoxide is used to test the rate of diffusion.
What is KCO
TLCO that is corrected for lung volume
What might cause a high KCO and normal/reduced TLCO?
- Pneumonectomy/lobectomy
- Scoliosis/kyphosis
- Neuromuscular weakness
- Ankylosis of costovertebral joints, e.g. ankylosing spondylitis
Causes of raised TLCO
- Asthma
- Pulmonary haemorrhage (Wegener’s, Goodpasture’s)
- L->R cardiac shunts
- Polycythaemia
- Hyperkinetic states
- Male gender
- Exercise
Causes of reduced TLCO
- Pulmonary fibrosis
- Pneumonia
- Pulmonary emboli
- Pulmonary oedema
- Emphysema
- Anaemia
- Low cardiac output
Secondary pulmonary fibrosis
Causes
- Alpha-1 antitripsin deficiency
- Rheumatoid arthritis
- Systemic lupus erythematosus (SLE)
- Systemic sclerosis
Extrinsic allergic alveolitis / Hypersensitivity pneumonitis
Pathophysiology
- Hypersensitivity induced lung damage due to inhaled organic particles
- Largely caused by immune-complex mediate tissue damage (type III hypersensitivity)
Extrinsic allergic alveolitis / Hypersensitivity pneumonitis
Examples
- Birds fancier lungs (avian proteins from bird droppings, chlamydia psittaci)
- Farmers lung (spores of saccharopolyspora rectivirgula from wet hay)
- Malt workers lung (aspergillus clavatus)
- Mushroom workers’ lung (thermophilic actinomycetes)
Cryptogenic Organising Pneumonia
What
Dx
Tx
What?
- Focal area of inflammation of the lung tissue
Dx:
- Present similarly to pneumonia
- Lung biopsy is definitive Ix
Tx
- Systemic corticosteroids
Asbestosis
Pathophysiology
- Inhalation of asbestos
- Fibrogenic to lungs
- Oncogenic too
- Effects usually take decades to develop
Asbestosis
Features
- Pleural plaques (benign, do not undergo malignant change, do not require follow up, occur after latent phase 20-40yrs)
- Pleural thickening
- Lung fibrosis
- Asbestosis (severity is linked to length of exposure, latent period 15-30 yrs, lower lobe, SOB and reduced exercise tolerance)
- Adenocarcinoma
- Mesothelioma (malignant disease)
Mesothelioma
Which asbestos is most dangerous?
Crocidolite (blue)
Mesothelioma
Features
- Progressive SOB
- Chest wall pain
- Pleural effusion (generally painless)
- Clubbing
- Weight loss
- Hx of asbestos exposure in 85-90% (latent period of 30-40 years)
Mesothelioma
Tx
- Palliative chemo
- Limited role for surgery/radiotherapy
- Industrial compensation